US8285135B2ActiveUtilityA1
Method and device for adjusting weighting values in light metering
Est. expirySep 1, 2029(~3.1 yrs left)· nominal 20-yr term from priority
G03B 7/09979G03B 7/08
58
PatentIndex Score
2
Cited by
10
References
14
Claims
Abstract
A method for adjusting weighting values in light metering is provided. An input image is divided into multiple metering zones. The input image includes a number of pixel data, and the metering zones correspond to a number of exposure weighting values. It is determined whether the color of each pixel datum of the input image is skin color. For each metering zone, an amount of the pixel data determined as the skin color is calculated. The corresponding exposure weighting values of the metering zones are adjusted according to the calculated results.
Claims
exact text as granted — not AI-modified1. A method for adjusting weighting values in light metering, comprising:
dividing an input image into multiple metering zones, the input image including a plurality of pixel data and the metering zones corresponding to a plurality of exposure weighting values;
determining whether color of each pixel datum of the input image is skin color;
determining the color of each pixel datum which is determined to be skin color again according to a determination result of the pixel datum and determination results of a plurality of neighboring pixel data, wherein if the pixel datum and its neighboring pixel data are all determined as skin color pixels, confirming that the pixel datum is a skin color pixel and if at least one of the pixel datum and its neighboring pixel data is determined as not skin color pixels, confirming that the pixel datum is not a skin color pixel;
calculating an amount of the pixel data determined as the skin color for each metering zone; and
adjusting the corresponding exposure weighting values of the metering zones according to the calculated results, wherein the step of determining whether the color of each pixel datum of the input image is skin color comprises
for a piece of pixel datum, calculating a first reference value and a second reference value according to ratios among a plurality of sub-pixel data of the pixel datum; and
determining whether the first reference value and the second reference value are within a predetermined region, wherein the first reference value and the second reference value are calculated as follows:
the
first
reference
value
=
(
R
input
G
input
)
2
+
(
R
input
B
input
)
2
-
1.4
the
second
reference
=
tan
-
1
(
(
R
input
B
input
)
/
(
R
input
G
input
)
)
-
0.7
R input , G input , B input indicate three sub-pixel data of the piece of pixel datum, respectively.
2. The method for adjusting weighting values in light metering according to claim 1 , further comprising:
sequentially obtaining the pixel data of the input image from an image sensor unit,
wherein the image sensor unit is implemented by a complementary metal-oxide-semiconductor (CMOS) sensor or a charge-coupled device (CCD) sensor.
3. The method for adjusting weighting values in light metering according to claim 1 , wherein the neighboring pixel data are a plurality of previous pixel data.
4. The method for adjusting weighting values in light metering according to claim 1 , wherein, in the step of calculating an amount of the pixel data determined as the skin color for each metering zone, calculated is a ratio of the amount of the pixel data determined as the skin color in each metering zone to the amount of overall pixel data in each metering zone.
5. The method for adjusting weighting values in light metering according to claim 1 , wherein, in the step of adjusting the corresponding exposure weighting values of the metering zones according to the calculated results, higher exposure weighting values are assigned to metering zones having higher amount of the pixel data determined as the skin color.
6. The method for adjusting weighting values in light metering according to claim 1 , wherein the pixel data of the input image are obtained according to a plurality of first exposure weighting values which correspond to the metering zones, and the step of adjusting the exposure weighting values for the metering zones includes:
generating a plurality of second exposure weighting values which correspond to the metering zones according to the calculated results; and
determining the corresponding weighting values of the metering zones according to the first exposure weighting values and the second exposure weighting values of the metering zones.
7. The method for adjusting weighting values in light metering according to claim 1 , wherein the step of determining whether the color of the pixel data of the input image is skin color comprises:
Skin
Pixel
=
{
1
,
if
0
≤
K
≤
2.1
and
0
≤
Z
≤
0.35
0
,
otherwise
K is the first reference value and Z is the second reference value;
the predetermined region is a section where the first reference value ranges between 0 and 2.1 and the second reference value ranges between 0 and 0.35;
if Skin Pixel is 1, the determining step determines that the color of the pixel data is skin color; and
if Skin Pixel is 0, the determining step determines that the color of the pixel data is not skin color.
8. A device for adjusting weighting values in light metering, dividing an input image into multiple metering zones and adjusting corresponding weighting values of the metering zones, the input image including a plurality of pixel data, the device comprising:
a determination unit for determining whether color of each pixel datum of the input image is skin color;
a filter unit for determining the color of each pixel datum which is determined to be skin color again according to a determination result of a pixel datum and determination results of a plurality of neighboring pixel data, provided by the determination unit, wherein if the pixel datum and its neighboring pixel data are all determined as skin color pixels, confirming that the pixel datum is a skin color pixel and if at least one of the pixel datum and its neighboring pixel data is determined as not skin color pixels, confirming that the pixel datum is not a skin color pixel;
a calculation unit for calculating an amount of the pixel data determined as the skin color for each metering zone;
a weighting adjustment unit for adjusting the corresponding exposure weighting values of the metering zones according to the calculated results; and
a color ratio calculation unit for calculating a first reference value and a second reference value according to ratios among a plurality of sub-pixel data of a pixel datum,
wherein in determining whether the color of each pixel datum is skin color, the determination unit determines whether the first reference value and the second reference value are within a predetermined region, and the first reference value and the second reference value are calculated as follows:
the
first
reference
value
=
(
R
input
G
input
)
2
+
(
R
input
B
input
)
2
-
1.4
the
second
reference
=
tan
-
1
(
(
R
input
B
input
)
/
(
R
input
G
input
)
)
-
0.7
R input , G input , B input indicate three sub-pixel data of the piece of pixel datum, respectively.
9. The device for adjusting weighting values in light metering according to claim 8 , wherein:
the color ratio calculation unit is coupled to an image sensor unit so as to sequentially obtain the pixel data of the input image from the image sensor unit; and
the image sensor unit is implemented by a complementary metal-oxide-semiconductor (CMOS) sensor or a charge-coupled device (CCD) sensor.
10. The device for adjusting weighting values in light metering according to claim 8 , wherein the neighboring pixel data are a plurality of previous pixel data.
11. The device for adjusting weighting values in light metering according to claim 8 , wherein the calculation unit further calculates a ratio of the amount of the pixel data determined as the skin color in each metering zone to the amount of overall pixel data in each metering zone.
12. The device for adjusting weighting values in light metering according to claim 8 , wherein if the weighing adjustment unit adjusts the corresponding exposure weighting values of the metering zones, higher exposure weighting values are assigned to metering zones having higher amount of the pixel data determined as the skin color.
13. The device for adjusting weighting values in light metering according to claim 8 , wherein:
the pixel data of the input image are obtained according to a plurality of first exposure weighting values which correspond to the metering zones;
the weighting adjustment unit generates a plurality of second exposure weighting values which correspond to the metering zones according to the calculated results of the calculation unit; and
the weighting adjustment unit determines the corresponding weighting values of the metering zones according to the first exposure weighting values and the second exposure weighting values of the metering zones.
14. The device for adjusting weighting values in light metering according to claim 8 , wherein
Skin
Pixel
=
{
1
,
if
0
≤
K
≤
2.1
and
0
≤
Z
≤
0.35
0
,
otherwise
K is the first reference value and Z is the second reference value;
the predetermined region is a section where the first reference value ranges between 0 and 2.1 and the second reference value ranges between 0 and 0.35;
if Skin Pixel is 1, the determining unit determines that the color of the pixel data is skin color; and
if Skin Pixel is 0, the determining unit determines that the color of the pixel data is not skin color.Join the waitlist — get patent alerts
Track US8285135B2 — get alerts on status changes and closely related new filings.
We store only your email — no account needed. See our privacy policy.